Can't be sure, but a website says "L-Theanine (5-N-ethylguatamine) is a unique free-form amino acid found in green tea. L-Theanine is the predominant amino acid in green tea and makes up 50% of the total free amino acids in the plant."

So that's what causes the relaxed feeling when drinking green tea. And it wasn't just me when I felt like I could concentrate better in school when I drink green tea instead of black tea or coffee in the morning.

So that's what causes the relaxed feeling when drinking green tea. And it wasn't just me when I felt like I could concentrate better in school when I drink green tea instead of black tea or coffee in the morning.

What an old thread! But thanks Warden, very interesting read. I'm sure that if green tea contains L-theanine, then white tea must also, as they're processed similarly. But I wonder if more oxidized teas (black, oolong) or "post-fermented teas" (pu-erh) contain L-theanine and, if so, is it in the same amounts or is the L-theanine altered by the processing.

I love this thread! It refuses to die. You have to admire the sheer tenacity of a thread like this one. The staying power..... the determination....

Brain chemistry and tea. What a combo! I'm suprised that this thread hasn't brought out our chemistry enthusiasts. I remember being quite struck by the mood altering effect of green tea when I first started to drink it. Now I notice it less. Probably because my baseline mind/body is now more in line with the state of mind that drinking tea helped to produce in the first place. It's official - I have tea brain.

l-theanine capsules don't work. If your looking for a "high/buzz," matcha is your best bet as far as teas. If your searching to replace somethng St. John's Wort: herbal chillpills
Kava Kava: The tea gave me a chill feeling, but the pills don't work
Valerian Root: Calming/Drowsy

It's like the man who found out Lays Potato Chips were laced with cocaine. "No wonder I couldn't eat just one!" ><; But to be honest, I'm not surprised. But I don't know if this calming effect cause by this amino acid is substantial enough to account for the fact that Green and White tea taste good.